Cathcart said: “Contrary to the impression given by much of the British national press, Lord Justice Leveson did not propose, and Parliament has not approved, any measure that gives politicians powers over the press.”

He added that the new legislation and the removal of the Press Complaints Commission would be “an advance for UK press freedom”.

The Royal Charter proposes a new system of press regulation and is due to be presented to the Queen on 8 May.

New legislation means the Royal Charter can only be changed with a two-thirds majority of both houses of Parliament. There is also a proposed amendment to the Crime and Courts Bill which means that news organisations outside the state-recognised press regulator could be at risk of exemplary damages and increased costs in libel cases.

I note that you have written to David Cameron warning that the cross-party agreement on press self-regulation reached in Britain last month might send the wrong message to countries where press freedom is fragile. You say that ‘any attempt, no matter how well-intentioned, to embed press regulation in law has far-reaching implications for press freedom across much of the world’.

Nothing in the actions taken by the British Parliament last month could reasonably give encouragement to regimes wishing to curb the press. It is simplistic and erroneous interpretations of those actions – interpretations encouraged by British news organisations that have brought shame on journalists everywhere – that risk causing the damage you warn of. I urge you to examine the facts more closely and reconsider your position.

Contrary to the impression given by much of the British national press, Lord Justice Leveson did not propose, and Parliament has not approved, any measure that gives politicians powers over the press. The need to protect press freedom is taken as sacred in the Leveson report, and nothing in the charter impinges upon it.

The charter excludes politicians from any role in press self-regulation – an advance for UK press freedom, since the discredited Press Complaints Commission was chaired for almost all its existence by active politicians. You note that the charter is underpinned in statute but you do not say why. The reason is that without such an underpin the charter would be wide open to amendment by ministers. Thus the underpin protects press freedom.

There is nothing in the new arrangements to comfort would-be dictators, and by suggesting otherwise you appear to embrace the rhetoric of British newspapers which, as Sir Harold Evans has pointed out, have been guilty of staggering misrepresentation of the Leveson recommendations.

I would like to raise some further points of fact and interpretation.

You write of a ‘deal’ that was ‘struck’ with opposition parties, as if this were improper. The agreement between the three main parties was approved the next day by Parliament in fully constitutional fashion, with I believe the support of every single party down to the very smallest. A key vote was carried by 530 to 13. It is rare for any measure to command such consensus.

You speak of the ‘haste’ with which the deal was done. The Leveson recommendations were the fruit of a public inquiry lasting 14 months to which every interested group including the press gave their views. What followed was not haste but four months of delay as Mr Cameron considered making a shabby deal with the very newspaper groups that had been condemned by the inquiry for ‘wreaking havoc in the lives of innocent people’.

You write that it would be ‘highly regrettable’ if authoritarian leaders ‘could point to the British parliament as precedent for introducing statutory media controls or regulations’. It would indeed, but as I have explained there is no such precedent. You write that leaders in Hungary might rejoice that Britain was ‘taking the first step down the path to media regulation’. Again they might, but Britain is not taking that step.

You write that ‘many responsible journalists in Britain acknowledge the sins of Fleet Street, but most argue that these can be addressed through existing legislation’. There is no evidence for that. The country’s largest organisation for journalists, the National Union of Journalists, with more than 30,000 members, has welcomed the charter agreement. Nick Davies, the Guardian reporter who broke open the hacking scandal, has endorsed Leveson’s proposals.

Existing laws did not prevent the evolution of newsroom cultures that encouraged systematic data-mining, phone hacking and the use of private investigators by editors. Nor did they prevent the harassment, bullying, distortion and intrusion that were the hallmark of those newsrooms. Nor did existing libel law deter newspapers: one group alone lost or settled 26 actions in 34 months, indicating that it had effectively built libel costs into its budget.

You suggest that Mr Cameron should ‘make the civil law more accessible to the victims of unscrupulous newspapers’. That is precisely what the charter does: it creates for the first time an arbitration service where people with causes in law may have their cases heard swiftly and without charge. This, incidentally, would also be a boon to newspapers.

As for the Defamation Bill, it was principally to improve access to justice that it was amended, but you have misunderstood this. The Bill was jeopardised by Mr Cameron, who refused to pass the amendments into law. And it is thanks to the cross-party agreement that the Defamation Bill is now able to progress.

These are not mere details, but there are bigger questions here. Your letter barely mentions the outrages which gave rise to the Leveson inquiry and it leaves the strong impression that you have not given them, or the victims, serious consideration. Does CPJ believe that Britain should have done nothing to protect its citizens from organisations that have bullied and mistreated them and disgraced journalism in the process? Does it really think that a raft of new civil and criminal laws is the answer? How concerned is CPJ about the corrosive effect on conscientious British journalism of practices that are often not illegal but must be considered repulsive in every civilised society? What kind of example do these practices set to the world?